Currently, Picky supports index reloading (since 1.4.2), and realtime indexes (since 3.1.10).
Index Reloading is about having a running system which is able to reload the generated indexes into the memory at runtime. Picky supports this since 1.4.2 by way of signals. Also, a Redis index backend solution (1.5.0+) updates the indexes instantly as you index.
Realtime indexes are about having any changes indexed instantly. There are very few real realtime indexing search engines. Picky is supporting this.
But, I cannot currently support an ActiveRecord etc. solution that hooks into the models, as manpower is very limited atm. An idea would be to simply notify Picky of changes (via Redis Pubsub or similar etc.) and use the Index#replace method to update the index.